effect of ferric carboxymaltose on exercise capacity after kidney transplantation

Conditions: Iron-deficiency; Transplant-Related Disorder

Summary: iron deficiency is common in kidney transplant recipients and is associated with impaired exercise tolerance and an unfavourable prognosis. this multicentre double-blind, placebo-controlled randomized controlled clinical trial will allow the investigators to analyse the effects of intravenous iron correction with ferric(iii) carboxymaltose on exercise tolerance and other parameters, in comparison to a placebo.

rationale: iron deficiency is common in kidney transplant recipients. the presence of iron deficiency is associated with an unfavourable prognosis in these patients. in patients with heart failure and iron deficiency, treatment with intravenous iron improved exercise capacity and quality of life. whether such beneficial effects may also occur in kidney transplant recipients is unknown. objective: our main objective is to address whether correction of iron deficiency with ferric(iii) carboxymaltose improves exercise tolerance and quality of life in iron-deficient kidney-transplant recipients. study design: a multicentre double-blind, placebo-controlled randomized controlled clinical trial will be performed to compare the effects of ferric(iii) carboxymaltose with placebo. study population: 158 iron-deficient kidney transplant recipients. the intervention arm will receive 10 ml of ferric(iii) carboxymaltose (50 mg fe3/ml, intravenously) every six weeks, with a total of four dosages. the control arm receives an intravenous placebo solution (saline). main study parameters/endpoints: the primary endpoint is the distance walked in six minutes, as quantified by the six-minute-walking-test at the end of follow-up. the investigators expect that iron-deficient kidney transplant recipients will benefit from ferric(iii) carboxymaltose treatment as a result of an improvement in exercise tolerance and general wellbeing.

Eligibility criteria:
inclusion criteria: * kidney transplant recipient * iron deficiency, defined by a ferritin level of ≤100 ug/l, or 100-299 ug/l combined with a transferrin saturation of ≤20% * at least six months after transplantation at baseline * age ≥18 years * ability to comply with the study protocol * informed consent exclusion criteria: * intolerance to any intravenous iron solution * severe anemia (hb \<10.5 g/dl, \<6.5 mmol/l), microcytic anemia (mcv \<80 fl) or progressive anemia (˃3.2 g/dl per month decline for two months or more) * a positive feces occult blood test or otherwise demonstrated gastrointestinal, or urogenital, blood loss * blood transfusion in the past six weeks * polycythemia (hb \>15.3 g/dl, 9.5 mmol/l) * estimated glomerular filtration rate (egfr) of ≤ 30 ml/min per 1.73 m2 * history of haemochromatosis * unstable angina or myocardial infarction during the previous month * disability to walk * severe hypophosphatemia in the month before baseline (serum phosphate \<0.35 mmol/l) * pregnancy or inability to take adequate contraceptive measures when at childbearing age (women) * any signs of an active systemic infection * participation in another interventional study

Keywords: renal transplantation kidney transplantation iron deficiency